A STUDY  OF  THE  PRODUCTS  OB- 
TAINED BY  THE  SOLVENT  AC- 
TION OF  DIPHENYL  ETHER 
ON  A UTAH  COAL 

BY 


JAMES  REMINGTON  SMITH 


THESIS 


FOR  THE 


D EGREE  OE  BACHELOR  OF  SCIENCE 


CHEMISTRY 


COLLEGE  OF  LIBERAL  ARTS  AND  SCIENCES 


UNIVERSITY  OF  ILLINOIS 


1922 


/92  2. 
-S  m 6 


UNIVERSITY  OF  ILLINOIS 


I92_  J«t_ 


THIS  IS  TO  CERTIFY  THAT  THE  THESIS  PREPARED  UNDER  MY  SUPERVISION  BY 



ENTITLED A_  _ L_l_  k*i  _ jk  il  _ i ik  _ _ j VIS.  4i~Q_A§  __________  Qv.4 kiiiU;  

Ar>+irin  rk-P  ni  nhonnl  tt  •*->.«».  nrnn  -j  TT-t-aVi 

_>£.■«.  i.  i ^ _ _-*.*»•_> 

IS  APPROVED  BY  ME  AS  FULFILLING  THIS  PART  OF  THE  REQUIREMENTS  FOR  THE 

degree  OF  __?-che  l_c_-__cX_r_aiiUi^ 

.sJZ— 

Instructor  in  Charge 

- V 

.C7>  . 

Approved 


ACTING  HEAD  OF  DEPARTMENT  OF  _5HMI_STRY. 


Digitized  by  the  Internet  Archive 
in  2015 


https://archive.org/details/studyofproductsoOOsmit 


TABLE  OB  CONTENTS 


I.  INTRODUCTION.  Page 

1.  Purpose  1 

3.  Historical  1 

II.  EXPERIMENTAL 

1.  Description  of  Coal  10 

2.  Method  of  extraction. 10 

3.  Diagram  of  apparatus  13 

4.  Examination  of  Products: 

A.  Ultimate  analysis 13 

B.  Fractional  Carbonizat ion 13 

C.  Coking  tests  13 

D.  Iodine  numbers  13 

E.  Special  tests  on  the  extract  14 

III.  DISCUSSION  OF  RESULTS 

1.  Diphenyl  ether  as  a solvent 23 

3.  Coking  tests  35 

IV.  CONCLUSIONS  37 

V.  BIBLIOGRAPHY 28 


A STUDY  OF  THE  PRODUCTS  OBTAINED  BY  THE 
SOLVENT  ACTION  OF  DIPHENYL  ETHER  UPON  A UTAH  COAL. 


I.  INTRODUCTION 


1.  Purpose. 

The  purpose  of  thi.s  investigation  is  a study  of  the 
extractable  material  and  the  insoluble  residue  obtained  by  the 
solvent  action  of  diphenyl  ether  upon  a Utah  coal  of  the  fat 
bituminous  type. 


2.  Historical. 

Considerable  investigation  has  been  carried  on  in  the 
past  along  the  line  of  determining  the  constitution  of  coal.  These 
studies  have  been  approached  from  three  view  points;  from  micro- 
scopic examination,  from  examination  of  the  decomposition  products 
obtained  by  fractional  distillation,  and  from  examination  of  the 
material  obtained  by  the  action  of  certain  solvents  and  reagents 
upon  coal.  Each  of  these  methods  have  contributed  a share  to  our 
knowledge  of  coal. 

The  use  of  solvents  dates  back  to  1851  at  which  time 

Dr,  Smythe1,  in  examining  a brown  coal  from  Brflhl,  near  Cologne, 

used  the  following  solvents:  benzene,  chloroform,  alcohol,  ether 

and  petroleum  ether.  He  obtained  a 3 per  cent  extraction  with 
benzene,  1.8  per  cent  with  chloroform  and  2.4  per  cent  with  alcohol. 

On  the  basis  that  these  extracts  were  pure  substances,  he  calculated 

from  percentage  composition,  the  formula  of  the  chloroform  extract 

a3  C15H24O2  and  of  the  benzene  extract  C^H^gOg. 


- 2 - 

o 

Anderson  and  Roberts  in  1898  subis  cted  Scotch  coals 
to  the  saponifying  action  of  caustic  potash  and  found  that  with  a 
semi -coking  coal  the  re sine id  bodies  were  saponified  and  all  cok- 
ing tendency  in  the  remaining  residue  destroyed  while  a 
strongly  coking  coal  only  partially  lost  it 3 coking  property,  or 
in  other  words,  only  part  of  the  resinic  material  in  a strongly 
coking  coal  is  saponifiable  with  caustic  potash. 

3 

Baker  in  1901  extracted  various  coals  with  pyridine. 

He  found  that  anthracite  coal  furnished  very  little  material  soluble 
in  pyridine  and  that  a bituminous  coal  was  soluble  to  the  extent 
of  20.4  per  cent.  An  ultimate  analysis  did  not  show  a concordant 
change  in  the  proportions  cf  elements  present  in  coal,  extract  and 
residue. 

4 

Anderson  and  Henderson  in  1903  extracted  coals  from 
Bengal,  Scotland  and  Japan  with  pyridine  and  found  that  the  extract 
from  all  of  these  coal 3 were  similar  in  character  and  possessed, 
after  the  removal  of  the  solvent,  a black  lustrous  appearance 
similar  to  bitumen.  The  percentage  in  extract  of  carbon,  hydrogen 
and  nitrogen  was  about  the  same  as  that  of  the  original  coal.  They 
found  that  the  coking  property  was  entirely  removed  from  a semi- 

coking  coal  but  only  partially  removed  from  a strongly  coking  coal. 

5 

Professor  Bedson  in  1903  obtained  with  pyridine,  an 
extraction  of  33-33  per  cent  of  a gas  coal,  and  from  7-39  per  cent 
of  cannel  coal.  He  shows  that  there  is  no  relation  between  the 
volatile  matter  of  the  coal  and  the  percentage  of  extractable 


material 


3 


S 

Professor  Lewfcs  in  1914  in  his  book  on  coal,  reviews 
some  of  the  work  done  up  to  the  time  on  extraction  of  coal  with 
pyridine.  He  states  that  the  coking  property  of  a serai-coking  coal 
could  be  entirely  removed  aid  that  of  a strongly  coking  coal  only 
partially  removed  by  the  solvent  action  of  pyridine.  He  believes 
that  this  constituent  in  a strongly  coking  coal  which  resists  the 
solvent  action  of  pyridine  and,  a3  Anderson  and  Roberts0  found, 
resists  the  saponifying  action  of  caustic  potash,  to  be  a "hydro- 
caroon  derived  from  the  resin  bodies,  and  that  in  a strongly  coking 
coal  they  condition  the  coking  after  the  unaltered  resins  have  been 
saponified  ...  ", 

Professor  Lew&s  criticises  the  U3e  of  pyridine  as  a 
solvent  on  the  basis  that  in  many  cases  the  resulting  insoluble 
residue  contains  a higher  volatile  matter  percentage  than  the  ori- 
ginal coal,  and  also  an  increase  in  nitrogen  content,  both  of 
these  facta  leading  to  the  inference  that  the  pyridine  forms  an 
addition  product  with  some  constituent  of  the  coal.  Regardless, 
however,  of  this  criticism,  he  still  regards  pyridine  and  aniline 

as  being  the  two  most  successful  solvents, 

7 

Wahl  in  1913  examined  the  solvent  action  of  pyridine 
upon  a number  of  continental  coals  and  confirmed  Bedson's  observa- 
tions that  there  is  no  relation  between  the  weights  of  extractable 
material  and  of  volatile  matter  of  the  coal.  Those  coals  which 
yielded  a large  amount  of  extract  did  not  lose  all  their  coking 
property,  'but  the  coke  from  the  remaining  residue  was  much  more 
compact  than  that  obtained  from  the  original  coal.  The  extract 


- 4 - 

yielded  an  extremely  ’’puffy”  coke,  and  upon  mixing  with  the  residue, 
the  original  coking  properties  of  the  coal  were  reproduced. 

Vignon3  in  1914  extracted  various  coals  with  aniline 
and  quinoline.  With  aniline  he  obtained  a 36,8  per  cent  extrac- 
tion of  rich  gas  coals,  7.3  per  cent  extraction  of  medium  coal  and 
1.8  per  cent  of  a lean  coal.  The  same  coal  which  yielded  3S.8  per 
cent  extraction  with  aniline,  yielded  only  17.3  per  cent  extraction 
with  pyridine;  however,  with  quinoline  the  coal  gave  a 47,3  per 
cent  extraction. 

9 

Fraser  and  Hoffman"  in  1913  tried  the  effect  of  a 
number  of  reagents  and  organic  solvents  on  coal  and  found  that 
pyridine,  aniline,  and  phenol  removed  the  largest  amount  of  soluble 
material.  Using  phenol  as  the  solvent  they  extracted  10.87  per 
cent  of  a Franklin  County  Illinois  coal  and  then  by  further  treat- 
ment of  the  extract  with  sodium  hydroxide  and  organic  solvents, 
they  were  able  to  isolate  certain  substances  which  they  believed 
were  approximately  pure  compounds  but  which  could  not  be  proven  so 
on  account  of  the  small  amount  of  material  at  their  disposal. 

Parr  and  Hadley^  in  1914  also  studied  the  solvent 
action  of  phenol  on  Illinois  coals.  They  were  able  to  obtain  from 
the  high  volatile  coals  a 35  to  40  per  cent  extraction,  from  medium 
volatile  coals  a 30  to  35  per  cent  extraction  and  from  the  rela- 
tively low  volatile  coals  a 30  to  30  per  cent  extraction.  They 
found  that  the  residue  left  after  extraction  did  not  coke  and  that 
the  extract  yielded  a very  fluffy  coke.  By  mixing  residue  and 
extract  they  were  able  to  reproduce  the  original  coking  properties 
of  the  coal. 


- O - 


11 

F.  Fischer  and  W,  Gludd  in  1917  extracted  coal  with 

benzene  under  a pressure  of  55  atmospheres  and  a temperature  of 

375°C  and  obtained  a 6.7  per  cent  extraction  of  the  raw  coal.  By 

pouring  the  extract  dissolved  in  a little  benzene  into  petroleum 

ether,  they  were  able  to  precipitate  out  about  50  per  cent  of  the 

extract.  They  found  that  this  precipitate,  when  dried,  was  a brown 

o o 

powder  which  softens  at  140  C,  and  melts  and  rune  at  180  C.  The 

portion  soluble  in  the  petroleum  ether,  upon  evaporation,  yielded 

an  oily  product  50  per  cent  of  which  was  volatile  in  steam. 

12 

Pictet  in  1918  extracted  large  amounts  of  a fat 
Sarre  coal  with  benzene  under  atmospheric  pressure,  but  was  only 
able  to  obtain  a. 25  per  cent  extraction.  By  anelvsis  of  the  con- 
stituents of  the  extract,  he  3hows  that  the  extract  is  identical 
with  vacuum  tar  and  concludes,  therefore,  that  the  hydrocarbons  in 

the  vacuum  tar  must  be  present  in  coal  as  such. 

13 

Bone  and  Sarjant  in  1919,  working  with  pyridine 
under  atmospheric  pressure,  extracted  30  to  33  per  cent  of  coals 
of  33.3  per  cent  volatiles.  By  carrying  on  the  extraction  for  a 
prolonged  period  in  sealed  tubes  at  a temperature  of  13D  to  150°C, 
they  were  able  to  increase  the  amount  of  extractable  material  to 
57-63  per  cent.  They  concluded  from  this  that  the  solvent  action 
of  pyridine  upon  a coal  substance  involves  in  addition  to  a rapid 
dissolving  of  the  resinous  material,  a simultaneous  and  much 
slower  unbuilding  or  depolymer i zing  of  the  whole  coal  structure, 
which  is  thus  gradually  brought  into  a more  soluble  condition. 

In  summarizing  the  work  on  solvents  we  see  that  by 
this  maan3  coal  has  been  separated  into  two  portions,  the  one 


- 3 - 

soluble  in  certain  solvents  and  known  as  the  resinic  portion,  and 
the  other  insoluble  and  known  as  the  cellulosic  or  humus  portion. 

In  a semi-coking  coal,  the  coking  power  is  entirely  lost  with  re- 
moval of  resinic  material,  while  in  a strongly  coking  coal,  the 

g 

coking  property  i9  only  partially  lost.  This  lead  Professor  Lewes' 
to  infer  that  a portion  of  the  resinic  material  resisted  the  solvent 
action  of  pyridine  and  saponification  action  of  caustic  potash,  and 
that  this  constituent  was  a hydrocarbon. 

On  the  assumption  that  the  bonding  material  i3  confined 
solely  to  the  tar  derived  from  the  coal  resins  and  hydrocarbons, 
Lewes  states  that  the  reason  for  the  non-coking  property  of  lignites 
and  younger  coals  is  due  to  an  excess  of  humus  bodies  which  on  dis- 
tillation yt«ld  no  bonding  material  in  the  residue  and  the  resinic 
cannot  supply  enough  bonding  material  to  give  more  than  a friable 
mas3.  As  the  coals  undergo  altered  conditions  of  temperature  and 
pressure,  the  humu3  bodies  are  further  decomposed,  resulting  in  a 
concentration  of  the  resinic  and  hydrocarbon  portion.  When  the  pro- 
portion of  resin  and  hydrocarbon  bodies  have  reached  the  right  ratio 
as  compared  with  the  humus  and  residuum,  a strongly  coking  coal 
results. 

Professor  Lewes  believes  that  the  resinic  material  is 
derived  from  the  resins,  gums  and  oils  present  in  the  original 
plant  life.  During  the  transition  period  from  a semi-coking  coal 
to  a coking  coal,  a portion  of  the  resinic  material  undergoes  de- 
composition to  yield  a hydrocarbon  which  is  responsible  for  the 
coking  of  the  insoluble  pyridine  residues  of  coking  coals. 

Dr.  Hager14  does  not  agree  with  Professor  Lewes  on  the 


- 7 - 

question  of  the  hydrocarbons  being  responsible  for  the  difference 

between  semi  and  strongly  coking  coals.  He  states  that  there  is 

no  evidence  of  such  hydrocarbons  beyond  mere  traces  in  coal,  and 

says  that  "the  same  phenomena  would  be  observed  if  the  so-called 

resin  bodies  on  3low  heating  etc.  are  decomposed  and  yield  among 

other  products,  a smaller  quantity  of  a resin-like  body  which  melts 

at  a higher  temperature.  ...  True  coking  coals  have  sufficient 

o 

rosin-like  bodies  to  yield,  after  heating  to  300  C.,  still  suffic- 
ient resin-like  bodies,  or  rather  bodies  that  would  melt  to  form 

Q 

coke  when  heated  to  330  C and  above,  whilst  the  feebly  coking  coals 

on  heating  give  the  same  kind  and  proportion  of  melted  bodies  from 

their  resin  but  not  sufficient  in  quantity  to  'melt*  or  render 

liquid  the  whole  material,  or  to  give  sufficient  luting  material 

to  form  a good  coke." 

, 12 

Arne  Pictet  claims  that  petroleums  — at  least  some 
of  them  — are  the  verible  tar  from  what  is  essentially  a low  tem- 
perature, dry  distillation  of  coal.  He  bases  his  claim  upon  the 
physical  resemblance  between  vacuum  tar  and  petroleum,  the  identity 
of  six  of  the  saturated' hydrocarbons  from  coal  with  certain  frac- 
tions of  American  petroleums,  and  the  finding  of  melene  in  Galla- 
cian  petroleum  as  well  as  coal.  By  identifying  the  benzene  extract 
with  vacuum  tar,  he  concludes  that  the  hydrocarbons  which  compose 
9S  per  cent  of  the  vacuum  tar  were  present  in  the  coal  as  such. 

His  work  is  thus  contradictory  to  Dr.  Hager* s views. 

15 

R.  Thiessen  w in  his  report  on  the  structure  in 
Paleozoic  Bituminous  Coal^  which  summarizes  his  extensive  study  of 
the  structure  of  coals  by  microscopic  examination,  proves  very  con- 


- 8 - 

clusively  that  the  bitumen  of  ooal  is  a degradation  product  of 
cellulose  and  his  views  are,  in  this  country  at  least,  supplanting 
those  of  Professor  Lewes. 

n r* 

David  White'*’”  in  1909  put  forth  a Il/o  ratio  theory 

for  the  index  of  the  coking  power  of  coal.  White  shows  that  as  the 

H/O  ratio  increases  the  coking  power  proportionally  increases,  that 

only  a few  coals  with  ratio  between  53  and  55  will  coke,  that  those 

between  55  and  SO  will  yield  only  a fair  coke,  and  as  the  ratio  in- 

17 

creases  to  above  60  the  quality  of  the  coke  increases.  White 
advocates  an  algal  theory  of  coal,  i.e.  that  micro-algae  form  the 
bitumen  part  of  coal,  and  that  those  coals  that  have  a high  vola- 
tile and  high  H/0  ratio,  and  correspondingly  high  coking  power,  have 
a high  content  of  these  micro-algae.  R.  Thiessen  finds  no  evidence 
of  algae  and  states  that  any  such  theory  could  not  be  demonstrated. 

From  White1 s work  we  see  that  coals  of  high  oxygen 
content  are  non-coking  or  feebly  coking  coals,  depending  on  the 
amount  of  oxygen.  The  effect  of  weathering  or  oxidation  upon  the 
coking  property  of  coal  has  been  known  for  a long  time.  Professor 

r% 

Lewes0  mentions  the  work  of  Dr.  Percy  *who,  more  than  fifty  years 
ago  pointed  out  the  fatal  effect  of  weathering  upon  certain  coals 
and  slacks,  and  who  showed  that  if  a fairly  good  coking  coal  were 
kept  at  a temperature  of  300°C  for  a few  hours,  and  wa3  later  heated 
to  redness,  it  did  not  swell  and  coke". 

Anderson  and  Roberts2  found  that  the  coking  property 
of  a 3emi-coking  coal  was  entirely  destroyed  by  subjecting  the  coal 
to  atmospheric  oxidation,  while  the  coking  power  of  a strongly  cok- 
ing coal  was  only  partially  destroyed  by  this  oxidation. 


'■n 

Professor  Lewes0  believes  that  "when  coal  absorbs 
oxygen  the  compressed  gas  becomes  chemically  very  active  and  soon 
commences  to  combine  with  the  hydrogen  and  carbon  of  the  resinic  por- 
tion, converting  them  into  carbon  dioxide  and  water  vapor". 

IS 

Boudouard' s work,  however,  shows  that  oxygen  attacks 
the  cellulosic  constituents  rather  than  the  resinic  and  he  reports 
the  formation  of  humic  acid  as  being  coincident  with  the  disappear- 
ance of  coking  power. 

11  14 

The  work  of  both  Hadley  and  Cherry  substantiates 
Boudouard' s views.  Cherry,  as  well  as  Hadley,  extracted  coal  with 
phenol  and  examined  the  products  of  extraction.  He  found  that  upon 
oxidation  cf  the  coal  the  first  constituent  to  be  affected  was  the 
cellulosic  portion  .and  that  in  the  first  stages  of  oxidation,  at 
least,  the  oxygen  absorbed  combines  additive Iv  with  the  unsaturated 
compounds  of  the  cellulosic  portion.  His  results  showed  that  "oxi- 
dation of  the  cellulosic  constituents  of  coal  alone  i3  sufficient  tc 
modify  the  coking  property  of  the  coal,  although  the  coking  principle 
is  contained  in  the  phenol  extract".  He  explains  the  above  facts  by 
assuming  "that  there  is  a reaction  at  fusion  temperatures  between 
the  oxidized  cellulosic  constituents  and  the  resinic  bodies,  whereby 
the  latter  are  so  altered  that  they  cannot  furnish  luting  material 
to  bind  the  particles  together". 


- 10 


III.  EXPERIMENTAL. 

1,  Description  of  Coal . 

0 

The  coal  used  was  a high  volatile  bituminous  coal  from 
Castle  Gate,  Utah.  Outcrops  of  resins  are  visible  throughout  the  cc 
mass  and  since  of  apparently  high  resinic  content,  this  coal  is  of 
particular  interest  as  it  retains  the  non-coking  property  character- 
istic of  the  western  or  younger  coals. 

2.  Method  of  Extraction 

The  coal  ground  to  pa33  through  a 100  mesh  sieve  was 
dried  in  100  grams  samples  for  3 hours  at  110°C,  Nitrogen  was 
passed  through  the  even  to  prevent  oxidation  of  the  coal.  By  dry- 
ing the  coal  before  extracting,  it  was  found  that  the  extraction 
could  be  accomplished  without  the  violent  bumping  that  would  other- 
wise attend  its  boiling. 

After  drying,  the  coal  was  introduced  into  a 750  cc. 
Pyrex  Erlenmeyer  flask  along  with  300  cc.  of  warm  diphenyl  ether. 

The  flask  and  contents  were  placed  in  an  electric  resistance  furn- 
ace, the  flask  connected  with  condenser  and  air  seal,  and  the  air 
displaced  from  the  apparatus  with  ethyl  ether.  All  connections 
were  coated  with  litharge  and  glycerol  mixture  to  make  tight  joints. 
The  temperature  of  the  furnace  was  then  raised  to  350-330° C and 
kept  between  these  temperatures  for  48  hears. 

After  extraction  the  contents  were  filtered  on  to  a 
quantitative  filter  paper  in  a four  inch  Buchner  funnel.  A slight 
amount  of  coal  will  come  through  at  first  but  as  soon  as  a coal 
layer  forms  on  the  filter  paper  the  solution  come 3 through  free  of 


- 11 


coal.  The  first  filtrate  i3  re-filtered  to  insure  complete  removal 
of  the  coal.  The  coal  was  then  washed  with  pure  hot  diphenyl  ether 
and  replaced  as  rapidly  as  possible  in  the  extraction  flask,  500  cc. 
of  warm  diphenyl  ether  mixed  with  it  and  the  coal  again  extracted. 

It  was  found  that  seven  extractions  of  48  hours  each  were  necessary 
tc  completely  remove  all  the  extractable  material. 

The  diphenyl  ether  solution  of  the  extract  was  con- 
centrated to  about  100  cc.  by  distilling  off  the  excess  solvent. 

The  seven  extractions  concentrated  in  this  manner  were  mixed  to- 
gether and  reconcentrated  to  about  100  cc.  and  then  poured  into  a 
300  cc.  straight  walled  beaker.  The  beaker  was  stoppered  and  placed 

Q 

in  the  resistance  furnace  whose  temperature  was  maintained  at  350  C. 
Preheated  nitrogen  was  passed  into  the  beaker  until  all  the  diphenyl 
ether  was  volatilized  off  and  no  odor  of  it  could  be  detected.  The 
extract  was  then  removed  from  beaker,  weighed  and  preserved  in 
nitrogen. 

The  insoluble  residue  was  washed  first  in  the  Buchner 

funnel  with  ethyl  ether  to  remove  the  most  of  the  diphenyl  ether, 

and  then  washed  in  a beaker  with  several  portions  of  ethyl  ether. 

The  ethyl  ether  was  then  filtered  off  and  the  residue  dried  in  an 

o 

atmosphere  of  nitrogen  for  4 hours  at  110  C.  The  residue  was  then 
weighed  and  preserved  under  nitrogen. 


. - 


■ 


- 12 


3.  Diagram  of  Apparatus. 


Resistance  furnace  male  of  60  ft.  of  No.  16  Chrcmel  wire 
(B)  wound  on  a 5 x 10  inch  sheet  iron  can  (H) , the  wires  being  im- 
bedded in  alundum  cement  (C).  The  furnace  is  packed  with  crude 
fibrous  »3oestos  (D).  The  temperature  of  the  furnace  is  controlled 
by  the  external  resistance  R. 

The  extraction  flask (A) is  a 750  cc.  Pyrex  Erlenmeyer  con- 
nected to  a 3 ft.  Pyrex  condenser.(F.) 

Constant  pressure  and  an  atmosphere  of  nitrogen  are  main- 
tained by  use  of  a i inch  water  seal  (F)  and  a solution  of  alkaline 
pyrogallol  (G). 


. 


- 13  - 

4,  Fx  an;  in  at ion  of  Products . 

A.  Ultimate  Analysis. 

B.T.U.  was  obtained  by  a Parr  Oxygen  Bomb,  total 
carbon  by  a Parr  Total  Carbon  apparatus,  nitrogen  by  Kjeldahl, 
sulfur,  moisture  and  ash  by  the  usual  methods,  and  oxygen  and  hydro- 
gen calculated  by  Dulcng*  s formula. 

B.  Fractional  Carbonization  ana  analysis  of  the  gaseous 
products. 

Carbonization  was  carried  on  in  a 150  cc.  Pyrex  dis- 
tilling flask  provided  with  a nitrogen  delivery  tube  and  connected 
to  first  a tar  well  and  then  calibrated  aspirator  bottles  containing 
saturated  3alt  solution  and  in  which  the  ga3e3  were  collected  and 
measured.  The  apparatus  was  swept  cut  before  and  after  each  determ- 
ination with  a measured  amount  of  nitrogen. 

The  gases  were  analyzed  in  a modified  Orsatt  apparatus. 
Carbon  dioxide  was  removed  with  caustic  potash  solution,  oxygen  with 
alkaline  pyrogallol,  unsaturated  hydrocarbons  with  bromine  water, 
aromatics  with  15  per  cent  fuming  sulfuric  acid,  hydrogen  and  carbon 
monoxide  by  means  of  combustion  at  300°C  with  copper  oxide,  and  the 
paraffins  by  slow  combustion  in  an  atmosphere  of  oxygen. 

C.  Coking  Tests. 

Coking  tests  were  made  in  one  gram  portions  in  an 
Illium  crucible  and  subjected  to  the  temperature  of  the  flame  of  a 
Meeker  burner  for  seven  minutes. 

D . I odi ne  Uurabe r s . 

19 

The  same  method  was  used  that  Cherry  1 found  to  be 
well  suited  to  coal.  The  iodine  solution  wa3  prepared  by  the  Hanus 


- 14 


method  .and  consisted  of  an  iodine  monobromide  solution  in  glacial 
acetic  acid.  Twenty  cc.  of  the  solution  was  added  to  .5  gram  of 
coal  extract  or  residue  in  a 500  cc.  Erlenmeyer  flask.  The  flask 
was  stoppered  with  a stopper  moistened  with  10  per  cent  potassium 
iodide  solution  and  allowed  to  stand  in  a dark  cool  place  for  1 
hour.  At  the  end  of  this  time  10  cc.  of  10  per  cent  potassium  iodide 
solution  were  added,  followed  with  200  cc.  of  water,  and  the  excess 
iodine  titrated  with  standard  l/lO  F so  diurn  thiosulphate  solution. 
Duplicate  blanks  were  run  with  each  determination. 

5.  Special  tests  on  the  extract. 

The  melting  point  ms  determined  by  supporting  a small 

"""  i 

lump  of  extract  in  a small  wire  loop  and  placing  in  the  chamber  of 
a resistance  furnace.  The  temperature  of  the  furnace  was  then 
gradually  increased  and  the  temperature  noted  when  the  extract  be- 
came soft  enough  to  run. 

Free  Carbon  was  determined  by  extracting  two  grams  of 
the  extract  in  a Soxhlet  extractor,  using  an  equal  mixture  of 
benzene  and  toluene  as  the  solvent.  The  residue  left  after  complete 
removal  of  a soluble  material  was  dried  in  an  atmosphere  of  nitrogen 
for  3 hours  at  120°C. 

Asphaltenes  were  determined  on  a 1 gram  sample  of 
extract  by  first  letoing  it  stand  for  48  hours  with  40  cc.  of 
petroleum  ether,  then  filtering  the  solution  and  residue  through 
\ two  thicknesses  of  filter  paper.  The  residue  remaining  on  the  fil- 
! ter  papers  were  then  washed  with  hot  benzene  and  the  benzene  wash- 
, ings  collected  in  a taxed  beaker.  The  benzene  was  volatilized  off 
in  an  oven  at  11C°C.,  the  flask  cooled  in  a desiccator  and  weighed. 


- 15 


Paraffins  were  determined  on  a 1 gram  sample  of  the 
extract  as  follows.  The  sample  was  placed  in  a 300  cc.  ^rlenmeyer 
flask,  25  cc.  of  gasoline  added  and  mixed  thoroughly  with  the  ex- 
tract and  then  40  cc.  of  fuming  sulfuric  acid  introduced.  The 
mixture  was  allowed  to  complete  sulphonation  "by  placing  flask  and 
contents  in  an  oven  at  110cC  for  one  hour  and  then  contents  were 
poured  into  Babcock  milk  dottles  and  enough  concentrated  fuming 
sulfuric  acid  added  to  fill  the  dottles.  The  dottles  and  contents 
were  centrifuged  and  clear  gasoline  solution  pipetted  off  the  acid 
layer  and  placed  in  a tared  flask.  The  gasoline  was  volatilized 
off  in  an  oven  at  15CUC,  the  flask  cooled  in  a desiccator  and 
weighed. 


- 16 


TABLE  I 

ULTIMATE  ANALYSIS 
As 


rec' d 
basis 

Moisture 

and  ash  free 
basis 

Coal 

Coal 

Re  si  due 

Extract 

Moisture 

3.35 

Total  Carbon 

70.80 

73.27 

71.71 

8 4.25 

Sulphur 

.40 

.42 

.45 

.38 

A.sh 

5.88 

S . 08 

S . 73 

.10 

Nitrogen 

1.30 

1.34 

1.32 

1.40 

Oxygen 

12.65 

13.08 

14.00 

5.09 

Hydrogen 

5.62 

5.81 

5,  80 

7.78 

B.T.U. 

13,835 

13,259 

13,965 

16,633 

Volatile  Matter 

•48.82 

44.31 

40.50 

67.75 

Fixed  Carbon 

47.95 

49.61 

53.78 

33.15 

- 17 


TABLE  II 

ULTIMATE  ANALYSIS 
(Moisture  Free) 
CALCULATED  TO  COAL  BASIS 


Residue 


Per  cent  in  coal 

93. SO 

Total  carbon 

67.33 

Sulphur 

.43 

A3h 

6.31 

Nitrogen 

cv 

• 

<h 

Oxygen 

13.15 

Hydrogen 

5.45 

B T 

•*->  • J-  • w • 

13,174 

Extract 

Sura 

Coal 

6.10 

100.00 

100.00 

5.14 

73,47 

73.37 

.03 

.44 

.42 

.00 

S • 31 

6.08 

.09 

1.33 

1. 34 

.37 

13.53 

13.08 

.47 

5.93 

5.81 

1,015 

13,  189 

13,259 

- 18  - 


TABLE  III 

GASEOUS  PRODUCTS  OF  FRACTIONAL  CARBONIZATION. 


For 

temperatures 

between  20°  and  375°C. 

Coal 

Re  3 idue 

Extract 

Per  oent  Gas 

Per  cent  Gas 

Per  cent  Gas 

C0o 

i 

1 C3 

• 

i to 
I to 

1 

54.4 

34.6 

°2 

3.0 

12.3 

19.3 

cnH3n 

3.9 

6.5 

1.9 

C6Es 

.9 

.0 

3.8 

h2 

4.2 

4.3 

11.6 

CO 

11.5 

17.0 

1.9 

CnH3n+-2 

38.3 

5.3 

23.  S 

Cc* 3 of  gas 
evolved  per 
10  grams  - - 

135 

70 

75 

- 19  - 


TA3LE  IV 

GASEOUS  PRODUCTS  OF  FRACTIONAL  CARBONIZATION. 


For 

■temperatures 

■between  375°  and  430° 

C. 

Coal 

Residue 

Extract 

Per  cent  Gas 

Per  cent  Gas 

Per  cent  Gas 

C02 

9.9 

31.1 

P P 

C • £> 

°3 

3.7 

2.3 

0 

to 

CnH3n 

9.4 

10.2 

7,3 

CSHS 

. 5 

.4 

3.1 

H3 

7.3 

7.0 

1.7 

CO 

7.3 

8.7 

5.9 

CnH3n+3 

31.9 

50.4 

70.1 

Cc* 3 of  gas 
evolved  per 
10  grams  — 

320 

270 

360 

- 30  - 

TAELS  V 

AMOUNT  OF  MATERIAL  EXTRACTABLE  WITH  DIPHENYL  ETHER 


Weight  of  coal  before  extracting IOC  grams 

Moisture  lost  in  drying  3.35  grams 

Weight  of  residue  91.02  n 

Weight  of  extract  5.30  " 


Burn  ICO.  27  " 

Per  cent  extraction  on  as  rec'i  basi3 5.90 

Per  cent  on  moisture  free  basis  3.10 

Per  cent  on  moisture  and  ash  free  basis 6.48 


TABLE  VI 
IODINE  NUMBERS 

Coal  Residue  Extract 

Gram 3 of  iodine  absorbed 

per  100  grams  of  sample  30.57  36.60  21.34 


TABLE  VII 


SPECIAL  TESTS  ON  T 

'HE  EXTRACT 

Free  Carbon  

34.10 

per  cent 

Asphaltenes  

31.68 

ft  n 

Paraffins  

1.15 

tt  ft 

Melting  Point  

....  220°  - 

350°  C. 

Description  of 

Extract 

Color  

black,  shiny 

Fracture  

concho id al 

Streak  

chocolate 

brown . 

r •:  . . t 


i 


31 


TA  2LE  VIII 
COKIITC-  TESTS 


Source 

of  residue 

> 

from 

Coun 

xylene  extraction  of  Franklin 
ty  Illinois  coal. 

Source 

of  extract 

from 

Utah 

diphenyl  ether 
coal. 

extraction  cf  a 

Test 

Residue 

Extract 

Volatile  Mtr. 

Character  of  re- 

No. 

Per  cent 

Per  cent 

Per  cent 

maining  residue. 

1 

100 

0 

45.33 

Powder . 

3 

95 

5 

43.  30 

Powder 

3 

SO 

30 

47,00 

Fair  coke,  silvery 

4 

70 

30 

49.70 

Resembles  test  3 onl 
coke  more  voluminous 

5 

50 

50 

58.10 

Resembles  test  4 only 
coke  more  voluminous 

7 

0 

100 

S7.75 

L i ght  and  f luf f y, 
shows  no  coke 
structure . 

- 23  - 

TABLE  IX 
COKING  TESTS 


Source  of  .residue 


Source 

of  extract 

extraction  of  Utah  coal 

Test 

Residue 

Extract 

Vo  1.  Mat  ter 

Character  of  remain- 

no. 

Per  cent 

Per Qent 

Per  c^nt 

ing  residue. 

1 

95 

5 

43.00 

Powder. 

3 

70 

30 

48 , 55 

?Feak  cake,  with  no 
coke  structure. 

3* 

70 

30 

— 

Same  as  test-  3. 

TABLE  X 
COKING  TESTS 


Source  of  residue  diphenyl  ether  extraction  of  Utah  coal. 

Source  of  extract  benzene  extraction  of  Franklin  County 

Illinois  coal. 

Test  Residue  Extract  Character  of  remaining 

no.  Per  cent  Per  cent  residue. 

1 70  30  Weak  cake,  with  no  coke 

structure 

2*  70  30  Same  as  test  1. 


♦in  test  3 Table  IX  and  test  2 Table  X,  the  unaltered  Utah 
coal  wa3  substituted  for  the  residue. 


- _ 

.IL/  *“ 


III.  DISUUSSION  OF  RESULTS 

1.  Diphenyl  ether  as  a solvent . 

From  Table  II  it  will  be  noted  that  the  sum  of  each 
constituent  in  the  ultimate  analysis  of  residue  and  extract 
approaches  the  percentage  of  that  constituent  in  the  original  coal 
within  experimental  error.  This  proves  that  diphenyl  ether  is  a 
neutral  solvent  and  neither  combines  with  or  decomposes  any  of  the 
products  present  in  the  coal  and  is,  therefore,  as  a true  solvent 
superior  to  pyridine,  aniline  and  quinoline. 

Diphenyl  ether  is  non-corrosive  to  the  skin,  is  of 
pleasant  odor,  is  easily  removed  from  both  extract  and  residue  with- 
out decomposition,  and  in  all  respects  is  an  easy  solvent  to  handle. 
Table  V shows  that  the  maximum  amount  of  solvent  retained  by  ex- 
tract and  residue  combined  is  .27  per  cent. 

The  percentage  of  material  extractable  by  its  solvent 
action,  though  not  as  great  as  compared  with  the  amount  obtained 
with  some  of  the  more  chemically  active  solvents,  compares  very 
favorably  with  the  best  of  neutral  solvents.  Because  of  its  high 
boiling  point  it  permits  a higher  obtainable  temperature  under 
atmospheric  pressure  than  the  lower  boiling  solvents  3uch  as 
benzene,  toluene,  etc.,  and  because  of  this  fact  a larger  percentage 

of  extractable  matter  can  be  obtained  with  diphenyl  ether  than  the 
lower  coiling  solvents,  extracting  under  atmospheric  pressure. 

The  fact  that  the  diphenyl  ether  no  longer  removes 
any  portion  of  the  remaining  residue  after  seven  extractions,  shows 
that  only  a definite  portion  of  the  original  coal  is  soluble  in 
this  solvent.  Table  I shows  that  the  analysis  of  this  soluble 


24 


constituent  is  of  the  general  composition  of  resinic  material. 

From  Table  VII  it  will  be  noted  that  the  asphaltene  content  i3 
comparatively  high  and  the  paraffin  content  low,  and  in  this 
respect  the  resinic  material  resembles  a true  bitumen. 

From  analysis  of  the  gaseous  products  of  carbonization 
of  extract,  residue  and  coal  in  Tables  III  and  IV,  two  facts  are  in 
evidence.  One  is  that  diphenyl  ether  removes  a constituent  which 
decomposes  to  liberate  paraffin  hydrocarbons  below  375°C  and  the 
other,  that  the  remaining  residue  evolves  large  amounts  of  CO  and 
C0o  below  375°C.  Since  the  melting  point  of  the  extract,  though  not 
definite,  is  in  the  neighborhood  of  320°  to  250°C,  and  since  para- 
ffins are  evolved  to  3ome  extent  below  375°C  with  the  percentage  in- 
creasing rapidly  as  the  temperature  increases  above  375°,  we  know 
that  the  resinic  material  starts  to  decompose  below  375°C  and  that 
its  pasty  period  is,  therefore,  below  this  temperature.  From  the 
second  fact  mentioned  above  it  is  evident  that  during  the  pasty  per- 
iod of  the  resinic  material,  the  cellulosic  portion  is  evolving  large 
volumes  of  CO  and  COo. 

By  the  comparison  of  iodine  numbers  we  note  that  the 

coal  and  extract  are  nearly  e-qual  in  unsaturation  while  the  residue 

is  decidedly  more  unsaturated.  Likewise  in  the  analysis  of  the 

gaseous  products  of  carbonization  it  can  be  noted  that  the  residue 

evolves  a larger  percentage  of  unsaturated  hydrocarbons  than  the 

19 

extract.  This  data  collaborates  the  results  obtained  by  Cherry  " and 
proves  that  the  cellulosic  portion  of  the  coal  is  more  unsaturated 
than  the  resinic. 


2«  Cokina;  Tests, 

Table  trill  shows  that  by  mixing  the  extract  from  the 
Utah  coal  with  residue  from  Illinois  coal,  a coke  is  obtained  that 
is  equal  in  strength  and  structure  to  the  coke  formed  when  an  equal 
amount  of  extract  from  Illinois  coal  i3  mixed  with  the  same  residue. 
This  proves  that  the  resinic  portion  of  the  Utah  coal  ha3  a bond- 

forming  value  equal  to  the  resinic  portion  of  the  Illinois  coal. 

3 

According  to  the  theory  of  Professor  Eswes  the  non- 
coking cf  the  younger  coals  is  due  to  the  predominance  of  the  humic 
or  cellulosic  portion  over  the  resinic  and  that  the  latter  is, 
therefore,  not  present  in  large  enough  quantity  to  furnish  the 
necessary  bonding  material.  If  his  theory  is  correct,  a coking 
property  should  be  obtained  by  merely  increasing  the  resinic  con- 
tent of  the  coal.  Tables  IX  and  X show  that  the  result  of  increas- 
ing the  resinic  content  to  30  per  cent,  or  10  per  cent  more  than 
was  necessary  to  coke  an  Illinois  residue,  did  not  increase  the 
coking  tendency  in  the  least.  In  making  these  determinations 
extract  from  both  Illinois  coal  and  Utah  coal  were  mixed  with 
first  Utah  residue  and  then  Utah  coal  to  prove  that  it  was  neither 
the  Utah  extract  or  a possible  oxidation  cf  the  residue  during 
extraction  that  was  responsible  for  the  non-coking. 

All  the  above  fact 3 prove  conclusively  that  the  non- 
coking of  the  Utah  coal  lies  in  the  fault  of  the  cellulosic  por- 
tion and  not  in  the  resinic  content. 

As  mentioned  previously,  we  note  a large  volume  of 
CO3  and  00  liberated  by  the  residue  under  3?5cC  or  during  the  range 
in  which  the  pasty  period  of  the  extract  is  in  evidence,  and  it 


- 26 


seams  possible  that  the  gases  liberated  by  the  cellulosic  portion 
during  the  forming  of  the  bonding  material  may  be  responsible  for 
the  destruction  of  the  coking  property.  Now  since  00,  C0_  and  Oo 
are  all  liberated  by  the  resinic  portion,  as  well  a3  the  cellulosic 
portion,  it  does  not  3sem  probable  that  these  same  gase3  liberated 
by  the  cellulosic  portion  should  have  any  chemical  effect  upon  the 
bond-forming  constituent.  It  doe 3,  however,  seem  plausible  that  a 
liberation  of  a large  volume  of  gas  around  the  cellulosic  portion 
during  the  pasty  stage  of  the  resinic  portion,  would  have  a pro- 
tective effect  on  the  cellulosic  portion  and  thus  prevent  the 
bonding  material  from  reaching  the  material  to  be  bonded.  As  the 
temperature  raises,  the  bonding  material  decomposes  and  loses  its 
bonding  power. 

Since  oxygen  and  its  oxides  of  carbon  constitute  84 

o 

per  cent  of  the  gases  evolved  under  375  , it  can  be  inferred  that 
the  high  oxygen  content  of  the  Utah  coal  is  responsible  for  its 
non-coking,  due  to  the  liberation  of  the  oxygen,  combined  or  free, 
in  the  form  of  gases  during  the  critical  time  when  the  resinic  por- 
tion is  in  the  bond -forming  stage.  This  theory  will  explain  the 
fact  that  all  young  coals,  being  high  in  oxygen,  and  likewise  oxi- 
dized coals,  will  not  coke  because  of  the  liberation  of  the  gaseous 
products  of  oxygen  in  large  volumes,  causing  a physical  repulsion 
of  the  bonding  material  away  from  the  material  to  be  bonded. 


37 


IV.  CONCLUSIONS 

1.  Diphenyl  ether  is  a true  solvent  and  neither  com- 
bines with  or  decomposes  any  constituent  of  the  coal.  It  is  easy 
to  handle  and  can  he  freed  from  both  extract  and  residue  without 
decomposition. 

2.  The  resinic  portion  of  the  Utah  coal  possesses  a 
bonding  power  equal  to  that  in  the  resinic  portion  of  a Franklin 
County  Illinois  coal  and  is,  therefore,  not  responsible  for  the 
non-ccling  of  the  Utah  coal. 

3.  The  non-coking  of  Utah  coal  lie 3 in  the  character 
of  the  cellulosic  portion. 

4.  The  hi  gh  oxygen  content  of  the  coal  i.3  responsible 
for  the  liberation  of  a large  volume  of  gas  during  the  pasty  period 
which  by  physical  repulsion  of  the  bending  material  away  from  cellu- 
losic portion,  prevents  the  formation  of  coke  structure. 


I 


. 


s . 

1 


28 


V.  BIBLIOGRAPHY 

I.  J.  Soc.  Chem.  Ind.  27,  14S  (1908). 

3.  " " " " 17,  1013(1898). 

3.  " " » " 30,  789  (1901). 

4.  " " " " 31,  343  (1902)  . 

5.  " " " " 27^  140  (1908). 

3.  The  Carbonization  of  Coal.  (1914). 

7.  Co  rip.  rend.  154.  1094  (1913). 

8.  »'  " 158,  1421  (1914). 

9.  Tech.  Paper  5,  U.S. Bureau  of  Mines,  (1913) . 

10.  Uni.  of  111.  Rxp.  Star.  Bull,  73  (1914). 

II.  Chain,  abstracts,  11,  1739  (1917). 

13.  Ann.  Chim.  10,  349  (1918). 

13.  Proc.  Roy.  Soc.  London,  98  A,  119  (1919). 

14.  Gas  World  SO,  18  5 (1914). 

15.  Bull.  117,  U. 8. Bureau  of  Mines  (1920). 

13..  Bull.  383,  U.S.  Geo.  Survey,  (1909). 

17.  Bull.  _38,  U.S. Bureau  of  Mines,  (1913). 

18.  Bull,  fe  la  Soc.  Cherr..  96  , 365  (1909). 

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